CN106532096A - A low-cost liquid flow battery negative electrode electrolyte and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of flow batteries, and discloses a low-cost negative electrode electrolyte and a preparation method thereof. The low-cost flow battery negative electrode electrolyte is prepared by taking a potassium hydroxide solution of organic micromolecule 1, 8-dihydroxy anthraquinone (DHAQ) as a negative electrode electrolyte. The preparation method of the low-cost flow battery negative electrolyte comprises the following steps: preparing a 1M KOH solution, adding an electrolyte raw material 1, 8-dihydroxy anthraquinone or a derivative or a mixture thereof into the 1M KOH solution, dissolving and mixing uniformly, and performing constant volume by using the 1M KOH solution to obtain the low-cost flow battery cathode electrolyte. The flow battery has the advantages of simple structure, low material price, high energy density and power density and the like, is 40% lower than that of an all-vanadium flow battery, and is very suitable for serving as large-scale electric energy storage equipment to realize peak load regulation and valley load filling of a power grid.

Description

A low-cost liquid flow battery negative electrode electrolyte and preparation method thereof

Technical field:

The invention relates to the field of liquid flow batteries, in particular to a low-cost liquid flow battery negative electrode electrolyte and a preparation method thereof.

Background technique:

With the increasing problems of resource shortage, environmental pollution, and population expansion, the original energy structure based on fossil fuels such as oil, natural gas, and coal can no longer meet the needs of human progress. Therefore, new energy sources are developed and wind energy and solar energy are fully utilized. Clean energy is imminent. However, both wind energy and solar energy are easily affected by the environment, resulting in intermittency and instability. In order to be truly applied in daily life, it is necessary to use cheap and high-performance energy storage technology to store energy when there is surplus energy. It can be used in case of power shortage, so as to realize the peak-shaving and valley-filling of the power grid, and ease the contradiction between power supply and demand.

In order to match the grid well, this energy storage technology needs to be cheap and capable of guaranteeing tens of hours of peak power discharge time. Most of the existing traditional batteries rely on metal elements, which are not only expensive, but also easily pollute the environment after being used and discarded. The discharge time at peak power is usually only tens of minutes, and cannot fully regulate the power generation of wind or solar power. In contrast, flow batteries are more promising, and their power capacity and energy storage capacity can be designed independently, so as to achieve tens of hours or even dozens of days of peak power discharge. The positive and negative active materials of the flow battery are stored in liquid storage tanks in liquid form, independent of the battery body, which can effectively avoid cross-infection of the positive and negative electrodes. The capacity of the storage tank can be arbitrarily designed according to the needs, and the storage location can be placed arbitrarily according to the terrain. . Electrodes are sized to match the required power output capability and generally do not participate in the reaction.

Therefore, as an efficient large-scale energy storage technology, flow battery technology has attracted the attention of more and more countries. However, the materials required for batteries, especially those metals used in redox reactions and noble metal materials used in catalysts, will generate hydrogen gas under acidic conditions, and the earth’s limited storage and high cost of use limit the large-scale use of flow batteries. . For example, the all-vanadium redox flow battery, which has attracted the most widespread attention, is the main problem that limits its development and large-scale application is the high cost. In addition, environmental protection is also a major consideration.

Invention content:

The purpose of the present invention is to reduce the cost of the liquid flow battery, maintain a high power density, and provide the negative electrode electrolyte of the above-mentioned low-cost high-specific energy flow battery. This electrolyte introduces the oxidation-reduction process of small organic molecules, which is low in cost, safe and non-toxic, does not require a catalyst, and uses an alkaline solution to make small organic molecules have a lower reduction potential. Another object of the present invention is to provide a method for preparing the anode electrolyte of the above-mentioned flow battery. This electrolyte employs, but is not limited to, 1,8-dihydroxyanthraquinone as an active substance. In the negative electrode electrolyte of the liquid flow battery, the concentration of 1,8-DHAQ is 0.01-1 mol/l. The invention belongs to the field of liquid flow batteries, and discloses a low-cost negative electrode electrolyte and a preparation method thereof. The negative electrode electrolyte of the low-cost flow battery is based on a potassium hydroxide solution of a small organic molecule 1,8-dihydroxyanthraquinone as the negative electrode electrolyte. The preparation method of the negative electrode electrolyte of the low-cost flow battery comprises the following steps:

Prepare a 1M KOH solution, add electrolyte raw materials into the 1M KOH solution, dissolve and mix evenly, and obtain the negative electrode electrolyte of the low-cost flow battery.

In the above preparation method, the electrolyte raw material includes 1,8-dihydroxyanthraquinone and its derivatives or multiple mixtures;

In the anode electrolyte of the claimed low-cost liquid flow battery, the concentration of 1,8-DHAQ is 0.01-1mol/l.

Advantages of the present invention: the present invention uses organic small molecule 1,8-dihydroxyanthraquinone and its derivatives as active materials in the negative electrode electrolyte of the flow battery, which greatly reduces the electrolysis rate of the flow battery while ensuring superior battery performance. Liquid cost, the cost can be reduced by about 40%. Relevant technologies can open up a new type of energy storage battery route that is safe, environmentally friendly, superior in performance, and low in cost, and eliminate energy storage obstacles in the current energy system and market demand. needs are of great significance.

Specific examples are as follows:

Example 1:

Weigh 28.05g KOH into a 250ml beaker, add appropriate amount of deionized water, stir to a constant volume of 500ml, weigh 0.6g1,8-DHAQ into a 250ml beaker, add an appropriate amount of 1M KOH solution, and stir to a constant volume of 250ml to prepare The low-cost liquid flow battery negative electrode electrolyte of the present invention is composed of 0.01 mol/l 1,8-DHAQ and 1.0 mol/l KOH.

Example 2:

Weigh 28.05g KOH into a 250ml beaker, add appropriate amount of deionized water, stir to a constant volume of 500ml, weigh 6g of 1,8-DHAQ into a 250ml beaker, add an appropriate amount of 1M KOH solution, stir to a constant volume of 250ml, and then prepare this product The negative electrode electrolyte of the low-cost liquid flow battery described in the invention is composed of 0.1 mol/l 1,8-DHAQ and 1.0 mol/l KOH.

The low-cost flow battery negative electrode electrolyte obtained in Example 2 was used to assemble a flow battery with K ₄ Fe(CN) ₆ , and the flow rates of both positive and negative electrodes were 60ml/min. The charge and discharge test of the flow battery is completed at a current density of 100mA/cm ² , and Figure 1 in the accompanying drawings is the charge and discharge test curve of the 1,8-DHAQ/K ₄ Fe(CN) ₆ flow battery .

Example 3:

Weigh 56.1g of KOH into a 250ml beaker, add appropriate amount of deionized water, stir to a constant volume of 500ml, weigh 60g of 1,8-DHAQ into a 250ml beaker, add an appropriate amount of 2M KOH solution, and stir to a constant volume of 250ml to prepare this product The low-cost liquid flow battery negative electrode electrolyte described in the invention is composed of 1 mol/l 1,8-DHAQ and 2.0 mol/l KOH.

The present invention is not limited to the above examples. Without departing from the scope of the present invention, any changes, substitutions and derivatives that do not deviate from the spirit and principles of the present invention can be made, and all should be equivalent replacement methods. Included within the protection scope of the present invention.

Claims (5)

1. A low-cost liquid flow battery negative electrode electrolyte, characterized in that: the low-cost liquid flow battery negative electrode electrolyte is an electrolyte obtained by using small organic molecules as active substances. 2. A low-cost flow battery negative electrode electrolyte according to claim 1, characterized in that 1,8-dihydroxyanthraquinone (1,8-DHAQ) is used as the active material. 3. The anode electrolyte of a low-cost flow battery according to claim 3, characterized in that: in the anode electrolyte of the low-cost flow battery, the concentration of 1,8-DHAQ is 0.01 -1mol/l. 4. The preparation method according to claim 4, characterized in that: the solution for dissolving the electrolyte raw material is a KOH solution. 5. The negative electrode electrolyte according to any one of claims 1-4 is used in a liquid flow battery system.